Writing instrument



Jan. 27, 1970 A. J. TESSIER 3,492,077

WRI TING INSTRUMENT Filed April 4, 1968 F I G. 2

37 3 F I G. 3

.FI G.4

INVENTORV ARAM J. TESSIER ATTORNEYS United States Patent 3,492,077 WRITING INSTRUMENT Aram J. Tessier, Warwick, R.I., assignor to T & T Mfg. Co., a corporation of Rhode Island Filed Apr. 4, 1968, Ser. No. 718,844 Int. Cl. B43k 21/02 US. Cl. 401-86 2 Claims ABSTRACT OF THE DISCLOSURE A writing instrument of the type in which there is a casing housing a marking member which is projected beyond the end of the casing for writing purposes and is retracted into the casing for carrying in the pocket with a deformable membento securely hold the mechanism for manipulating the marking member to the ornamental casing of the writing instrument.

BACKGROUND OF THE INVENTION So-called propel-repel writing instruments are manipulated by relatively rotating two parts of the instrument about a common axis. Generally the lower of the two parts is tapered in frusto-conical fashion and a marking implement projects therefrom. About the two parts of the writing instrument a casing is generally placed which casing is generally of two parts or sections, there being a lower part to envelop the lower portion of the writing instrument and an upper part to be frictionally engaged with the upper part of the writing instrument. In cases where a separate point is not utilized to secure the lower section of the writing instrument to the lower section of the case, it is common for the case to be tapered in conical fashion and to provide some means for securing the lower section of the casing to the lower portion of the writing instrument. Generally in the past a tapered bushing has been provided at the lower portion of the propel-repel mechanism and this bushing generally although not necessarily, has had attached thereto particularly in pencil-type mechanisms what is termed in the trade as a guide tube. Surrounding the lower bushing there has sometimes been provided an enlarged metal boss which has been knurled or otherwise roughened as by providing splines thereon so that a mechanical interlock would be provided between the lower end of the outer casing and the lower part of the writing instrument propelrepel mechanism. The additional mechanical operations that have to be performed on the bushing or lower end of the barrel and the fact that the two parts are being wedged together oftentimes deforms the outer casing in spite of the fact that the outer casing is held in a female die to prevent such deformation. Therefore, it is advisable to have a superior method of holding the lower end of the writing instrument to the lower end of the casing.

SUMMARY OF THE INVENTION A writing instrument which provides an inexpensive yet durable securing means for holding together the lower end of the lower portion of the propel-repel mechanism to the lower end of the casing. The lower end of the propel-repel mechanism is preferably formed with a pair of spaced ridges or stop rings and between these stop rings which serve as positioning devices a cylindrical separate bushing is placed, which bushing is formed of a thermoplastic material that exhibits very little stress relaxation when placed under compressive forces. Thus, such a type of thermoplastic material exhibiting this property will have good holding power for an interference fit between the lower end of the writing instrument mechanism and the casing.

3,492,077 Patented Jan. 27, 1970 DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a writing instrument;

FIG. 2 is a longitudinal view with the casing in section of the writing instrument which is the subject of this invention;

FIG. 3 is an elevational view partly in section of the writing instrument mechanism with the upper section broken ott to reveal the propel-repel mechanism;

FIG. 4 is an enlarged elevational view partly in section illustrating the lower end of the writing instrument with the casing secured thereabout; and

FIG. 5 is a perspective view of a deformable plastic collar.

DESCRIPTION OF THE PREFERRED EMBODIMENT The outer rigid casing of the writing instrument designated generally 10 comprises an upper section 11 and a lower section 12 having a writing end 13. The sections 11 and 12 are relatively rotatable so as to project the marking member to and from the casing. These outer sections are usually shells assembled over the working mechanism.

The working mechanism as shown in FIG. 2 within the shell or casing comprises a member 20 having a rigid cylindrical portion 21 tapered forwardly as at 22 to a guiding tube 23 through which the marking member, such as lead 24', extends. Rearwardly of this cylindrical portion 21, a flange 25 is formed which provides an abutment surface 26 facing the lower or writing end of the mechanism. A further retaining flange 27 spaced from the abutment surface 26 defines a rigid cylindrical collar receiving portion 28 from which ribs 29 project radially and about this portion 28 is a plastic collar 30 which becomes deformed as the mechanism is secured in the casing as will later be explained.

Member 20 also carries a longitudinally slotted tube 31 which embraces a carrier for a marking member having a finger projecting outwardly through the slot of such tube and into the helically slotted tube 35 which is fixed to another member 36 which is relatively rotatable with relation to the member 20. Member 36 has a cylindrical portion 37 engaging the plastic anti-friction washer 38 located between flange 25 and one end of portion 37 while it is provided with a knurled surface 39 over which the driving tube 40 extends and abuts a shoulder formed by the enlarged area 41 and is fixedly connected to this knurled portion 39 for relatively rotating the member 36 with reference to the member 20 so as to move the carrier for the marking lead 24 axially of the mechanism.

This driving tube 40 is expanded in size as at 42 and again as ribs as at 43 and over this ribbed portion the upper section 11 of the casing of the writing instrument is frictionally secured so that when this section is turned the driving tube 40 will be turned with it.

The member 20 is secured to the lower section of the casing 12 by a plastic member 30 (heretofore mentioned). It will be noted that the casing section 12 is tapered from a point about midway of its length to its lower writing end. The plastic member 30 referred to as a collar is in the first instance substantially cylindrical in shape, see FIG. 5, with a cylindrical opening of a size to just fit over the flange 27 by some slight enlargement and will be positioned in the area 28 defined between the flanges 25 and 27 and about the ribs 29. As this mechanism with the plastic collar 30 so positioned is inserted into the upper end of the casing section 12, it will engage the tapered surface 45 (see FIG. 4) and upon force being applied will be deformed in shape to assume the shape of a conical wedge as shown in FIG. 4 between this inner tapered surface 45 of the casing section 12 and the area 28 defined between the flanges 27 and 25. There will be a tendency for this plastic collar to move upwardly and engage the abutment surface 26, thus limiting its movement upwardly but it will deform itself upon compression into substantially the shape shown in FIG.'4 to tightly bind the member. 20 and the lower casing section 12 together so that rotation of the casing section 12 will cause rotation of the member 20 with it. Thus by relatively rotating the sections of the casing 11 and 12, the members 20 and 36 will be relatively rotated to project the carrier for the lead -24 into or out of writing position.

The plastic member 30 is a thermoplastic that exhibits very little stress relaxation when placed under compressive forces for an extended length of time and thus will maintain a uniform binding action upon both parts with which it engages. A material which I have found to be satisfactory for this purpose is an acetal copolymer marketed by the Celanese Corporation of America under the name Celcon and described in Bulletin C1A issued October 1964 by the Danielson Manufacturing Company a division of Nicholson File Company, Danielson, Conn.

I claim:

1. In a writing instrument having an upper end and a lower writing end, a marking mechanism having a lower writing end including a rigid cylindrical portion having an abutment thereon facing said writing end, a rigid casing for said mechanism comprising a casing section having an inner tapered surface, a thermoplastic collar about said mechanism adjacent said abutment and on the lower end side thereof, said collar being more deformable than the shell and casing and having the property of small stress relaxation, said collar being in compression between the cylindrical portion said mechanism and the tapered surface of said casing section to hold the engaged portion of said mechanism and said casing section to each other for rotation together.

2. In a writing instrument having an upper end and a lower writing end, a marking mechanism having a lower writing end and including a cylindrical portion With cylindrical ribs thereon and an abutment thereon facing said writing end, a flange spaced from said abutment toward the lower writing end, a casing for said mechanism comprising a casing section having an inner tapered surface, a plastic collar received about said cylindrical portion between said abutments, said collar wedged between said mechanism and the tapered surface of said casing section to hold the engaged portion of said mechanism and said casing section to each other for rotation together.

References Cited UNITED STATES PATENTS 1,515,615 11/1924 Pollak 40175 1,848,608 3/1932 Deli et al, 401-86 1,853,042 4/1932 Deli et a1. 40176 2,690,737 10/1954 Lynn 40163 2,883,967 4/1959 Tessier 401-86 LAWRENCE CHARLES, Primary Examiner 

